Anchoring device for a t-square



Oct. 13, 1959 H. M. BARRETT ANCHORING DEVICE FOR A T-SQUARE Filed Oct.29, 1956 Fl G. 3

FIG?

' INVENTOR HORACE M. BARRETT ATTORNEY '4 r l8 2 I aw a2 United StatesPatent 2,908,079 AN CHORING DEVICE FOR A T-SQUARE Horace M. Barrett,Oxford, Mass.

Application October 29, 1956, Serial No. 619,026 2 Claims. (CI. 33-76)This invention relates to a new and improved draftsmans instrument suchas a T-square, and particularly to anchoring means for securing arelatively small instrument in desired position directly upon a sheet ofdrawing paper whereby the draftsman is enabled to position his T-squarewhere desired without the necessity for using a straight edge or edge ofthe drawing-board, etc., and one of the principal features of thepresent invention resides in the provision of pressure-sensitiveadhesive means for detachably and replaceably positioning the T-squarewhere desired, so that the same may be used accurately at any place on alarge sheet of drawing paper and may be repositioned on the same sheetto a different location as often as may be needed.

Other objects and advantages of the invention will appear hereinafter.

Reference is to be had to the accompanying drawings, in which Fig. 1 isa plan view illustrating the T-square;

Figs. 2, 3, 4 and 5 are enlarged sectional views taken on the respectivelines of Fig. 1;

Fig. 6 is a plan view of a part of the device showing a modification,parts being broken away; and

Fig. 7 is an enlarged section on line 7 -7 of Fig. 6.

Referring to the drawings, the reference numeral 10 indicates generallya head or square for the T-square, the head or square being providedwith straight longitudinal edges 12 and 14 adjacent-top fiat surfaceswhich may be divided as desired in any scales.

The square 10 is provided with a more or less centrally arrangedlongitudinal undercut slot 16 which extends generally the length of thedevice except for the end portions thereof, and terminates in arectangular enlargement at 18 for a purpose to be described.

An elongated straight edge indicated at 20 is provided at one end aswith an enlargement 22 which has a transverse downwardly extendingdove-tail at 24. This dovetail is recessed from the flat bottom surfaceat 26 as clearly shown in Fig. 2, and by inserting the dove-tail 24 '10to insure accurate 90 positioning of the straight edge 20 relative tothe square 10.

The lower flat surface 26 is clearly co-planar with the lower flatsurface of the square 10, see Fig. 2, so that surface 26 is in contactwith the supporting surface for the instrument.

At each end portion of the head 10, there is provided a wedge-shapedopening passing entirely through the same, said opening preferably beingtapered as shown in Figs. 4 and 5 in order to wedgingly secure therein astrip of pressure-sensitive tape 34 as by means of a wedgeshaped blockor the like 36. This block may be provided with a handle 38.

In the use of the device, the square 10 is positioned where desired withreference to the portion of the drawing the draftsman may be working on,and it may be used 2,908,079 Patented Oct. 13, 1959 either in ahorizontal position as shown; or in a vertical position corresponding tothe position of the T-square head against the edge of the drawing-board;or the square 10 may be placed at any angle upon the drawing. In anyevent, the straight edge 20 is at an accurate rightangle with respect tothe length of the head and may be moved therealong as described. Bylightly pressing on the handle 38, the blocks 36 will press thepressuresensitive tape 34 down onto the paper upon which the draftsmanis working to lightly but firmly hold the square 10 in the exactposition desired.

When the draftsman wishes to re-position the device, it is merelynecessary to loosen the pressure-sensitive tapes 34 and then re-positionthe device wherever desired, using a fresh length of pressure-sensitivetape if necessary to once more hold the T-square head as described.

In the modification shown in Figs. ,6 and 7, the head 40 is similar tothat at 10, but in this case is not provided with blocks at the endportions thereof. Instead, pressuresensitive tape is provided which isadhesive on both sides thereof as represented by the reference numeral42. In this case, the blocks 36 are not necessary but the user merelypresses down upon the head 40 and the pressuresensitive tape 42 adheresboth to the under side of the head 40 and to the drafting paper uponwhich the draftsman is working.

It is pointed out that any other adhesive means may be used in order tohold the head 10 temporarily in position where desired, but it is notpossible to use suction cups or any device in which the lower edge 26 ofthe straight edge and also of the head is not flatly and firmly held onthe drawings, i.e. the entire T-square should be flat on the paper.Otherwise the draftsman will not be able to draw accurately. The entiredrawing instrument may be made of clear plastic so that it may bepositioned quickly and accurately.

7 Having thus described my invention and the advantages thereof, I donot wish to be limited to the details herein disclosed, otherwise thanas set forth in the claims, but what I claim is:

1. A T-square comprising an elongated grooved headment fitting theundercut groove for selective adjustment of the straight edge elementalong the head substantially from aperture to aperture, each aperturehaving spaced side walls in part defining the same, a strip ofpressuresensitive adhesive tape in each aperture with the tacky sidedown to contact said walls and a surface to which the T-square is to besecured by the tape, a separate handmanipulated element in each aperturefilling the same and holding the tape to said walls and to said surface,and means on the hand-manipulated elements by which to withdraw the samefrom its respective aperture to provide for separating the tape fromsaid surface and said walls.

2. The T-square of claim 1 wherein the apertures are wedge-shaped andthe hand manipulated elements compn'se wedges.

References Cited in the file of this patent UNITED STATES PATENTS826,425 Heathcote July 17, 1906 864,396 Weston Aug. 27, 1-907 1,115,333Pease Oct. 27, 1914 1,340,623 Owens May 18, 1920 1,343,968 Hahn June 22,1920 2,161,236 Shaw June 6, 1939 2,340,970 Lustrik Feb. 8, 19442,559,470 Schneider July 3, 1951

